Strollers, also referred to as push-chairs or prams, are commonly used to transport infants or toddlers. Foldable strollers offer the advantage of being easy to stow when not in use.
The state of the art includes U.S. Pat. No. 7,396,039 B2 (Valdez, et al.), describing an all-terrain baby stroller having a folding mechanism. The stroller comprises a foldable, tubular metal frame with a transversely extending rear axle assembly and a front wheel. The tubular frame includes left and right folding assemblies. Each of the folding assemblies includes two rotatable members, each having a disk with a notch and an arm; one arm being connected to the stroller handle and the arm being connected to the front wheel frame. The rotatable members, along with a corresponding rear wheel supports, are contained between housing halves that allow the arms to protrude outside of the housing. The inside wall of each half of the housing has a recess sized and shaped such that when the two halves of the housing are positioned together, the recesses form a cavity to securely receive the upper free-end portion of the rear wheel support. The disks are rotatable about a common bushing and may be interlocked by means of a spring-loaded tip mounted on the rear wheel support. The stroller may be folded by retracting the tip from the notches and rotating the disks with respect to one another, such that the front wheel support and the handle support are moved into close proximity to the rear wheel support.
The state of the art also includes U.S. Pat. No. 7,632,035 B2 (Cheng) which discloses a baby stroller having a folding mechanism. The folding mechanism includes a folding assembly having a first and second rotatable members rotatably mounted on an axle to rotate relative to each other. The first rotatable member is positioned for rotation in a first rotation plane and the second rotatable member is positioned for rotation in a second rotation plane, the first and second rotation planes are spaced apart. The first rotatable member has a first gear and the second rotatable member has a second gear. The folding assembly further has a third gear and a fourth gear configured to rotate together as a unit. The third gear is positioned in driving engagement with the first gear and the fourth gear is positioned in driving engagement with the second gear so that the first rotatable member and the second rotatable member rotate relative to each other in geared coordination.
The state of the art also includes U.S. Pat. No. 8,205,907 B2 (Chicca), describing a collapsible stroller having a frame with two so-called cam-fold units. Each cam-fold unit includes an inverse cam comprising a follower and a motion-transfer pin. Each of cam-fold units is coupled to the pusher handle and to the front wheel assembly and the rear wheel assembly. Each cam-fold unit includes a cam-support base, an inverse cam including a follower and a motion-transfer pin, and a pin mover. The cam-support base is coupled to the rear wheel assembly. The follower is coupled to the front wheel assembly so that the front and rear wheel assemblies move relative to one another when the follower is moved, by movement of the motion-transfer pin and pin mover. The pin mover is coupled to the pusher handle so that the pin mover moves relative to the rear wheel assembly to cause relative movement of the motion-transfer pin, follower, and front wheel assembly relative to the rear wheel assembly when the pusher handle is moved by a user relative to the rear wheel assembly.
The applicant has devised and embodied this invention to overcome certain shortcomings with the prior art and to obtain further advantages.